使用RecyclerView来完成聊天对话框

来源：互联网发布：游族网络手机官网编辑：程序博客网时间：2024/06/10 20:59

聊天记录信息类，该类中2个成员变量聊天内容content和信息来源type

public class Msg{    public static final int TYPE_RECEIVE = 0;    public static final int TYPE_SEND = 1;    private String content;    private int type;    public Msg(String content, int type)    {        this.content = content;        this.type = type;    }    public String getContent()    {        return content;    }    public int getType()    {        return type;    }}

定义一个适配器用于RecyclerView数据适配，根据信息来源不同，选择性显示聊天记录信息

/** * Created by Xiongxl on 2016/12/20. */public class MsgAdapter extends RecyclerView.Adapter<MsgAdapter.ViewHolder>{    List<Msg> msgList;    @Override    public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType)    {        View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.msg_item, parent, false);        return new ViewHolder(view);    }    @Override    public void onBindViewHolder(ViewHolder holder, int position)    {        Msg msg = msgList.get(position);        if (msg.getType() == Msg.TYPE_RECEIVE)        {            holder.leftLayout.setVisibility(View.VISIBLE);            holder.rightLayout.setVisibility(View.GONE);            holder.leftMsg.setText(msg.getContent());        } else if (msg.getType() == Msg.TYPE_SEND)        {            holder.rightLayout.setVisibility(View.VISIBLE);            holder.leftLayout.setVisibility(View.GONE);            holder.rightMsg.setText(msg.getContent());        }    }    public MsgAdapter(List<Msg> msgs)    {        this.msgList = msgs;    }    @Override    public int getItemCount()    {        return msgList.size();    }    static class ViewHolder extends RecyclerView.ViewHolder    {        LinearLayout leftLayout;        LinearLayout rightLayout;        TextView leftMsg;        TextView rightMsg;        ViewHolder(View view)        {            super(view);            leftLayout = (LinearLayout) view.findViewById(R.id.left_layout);            rightLayout = (LinearLayout) view.findViewById(R.id.right_layout);            leftMsg = (TextView) view.findViewById(R.id.left_msg);            rightMsg = (TextView) view.findViewById(R.id.right_msg);        }    }}

recyclerView项目内容的布局文件，包含一个左边的聊天记录和右边的聊天记录

<?xml version="1.0" encoding="utf-8"?><LinearLayout    xmlns:android="http://schemas.android.com/apk/res/android"    android:layout_width="match_parent"    android:layout_height="wrap_content"    android:orientation="vertical">    <LinearLayout        android:id="@+id/left_layout"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:layout_gravity="left"        android:background="@drawable/left">        <TextView            android:id="@+id/left_msg"            android:layout_width="wrap_content"            android:layout_height="wrap_content"            android:layout_gravity="center"            android:layout_margin="10dp"/>    </LinearLayout>    <LinearLayout        android:id="@+id/right_layout"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:layout_gravity="right"        android:background="@drawable/right">        <TextView            android:id="@+id/right_msg"            android:layout_width="wrap_content"            android:layout_height="wrap_content"            android:layout_gravity="center"            android:layout_margin="10dp"/>    </LinearLayout></LinearLayout>

项目的布局文件，布局文件中有一个recyclerView、EditText和一个Button用于信息发送触发事件

<?xml version="1.0" encoding="utf-8"?><LinearLayout    xmlns:android="http://schemas.android.com/apk/res/android"    android:layout_width="match_parent"    android:layout_height="match_parent"    android:orientation="vertical"    android:background="#d8e0e8">    <android.support.v7.widget.RecyclerView        android:id="@+id/msg_recyclerView"        android:layout_width="match_parent"        android:layout_height="0dp"        android:layout_weight="1"/>    <LinearLayout        android:layout_width="match_parent"        android:layout_height="wrap_content">        <EditText            android:id="@+id/input_text"            android:layout_width="0dp"            android:layout_height="wrap_content"            android:layout_weight="1"            android:hint="Type something here"            android:maxLines="2"/>        <Button            android:id="@+id/btnSend"            android:layout_width="wrap_content"            android:layout_height="wrap_content"            android:text="Send"/>    </LinearLayout></LinearLayout>

MainActivity活动内的代码代码如下

public class MainActivity extends AppCompatActivity{    List<Msg> msgList = new ArrayList<>();    EditText inputText;    Button btnSend;    RecyclerView recyclerView;    private MsgAdapter adapter;    @Override    protected void onCreate(Bundle savedInstanceState)    {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        initMsg();        btnSend = (Button) this.findViewById(R.id.btnSend);        inputText = (EditText) this.findViewById(R.id.input_text);        recyclerView = (RecyclerView) this.findViewById(R.id.msg_recyclerView);        LinearLayoutManager linearLayoutManager = new LinearLayoutManager(this);        recyclerView.setLayoutManager(linearLayoutManager);        adapter = new MsgAdapter(msgList);        recyclerView.setAdapter(adapter);        btnSend.setOnClickListener(new View.OnClickListener()        {            @Override            public void onClick(View view)            {                String content = inputText.getText().toString().trim();                if (!content.equals(""))                {                    msgList.add(new Msg(content, Msg.TYPE_SEND));                    adapter.notifyItemInserted(msgList.size() - 1);                    recyclerView.scrollToPosition(msgList.size() - 1);                    inputText.setText("");                }            }        });    }    private void initMsg()    {        Msg msg1 = new Msg("hello sealong", Msg.TYPE_RECEIVE);        msgList.add(msg1);        Msg msg2 = new Msg("hello peipei", Msg.TYPE_SEND);        msgList.add(msg2);        Msg msg = new Msg("What are you doing", Msg.TYPE_RECEIVE);        msgList.add(msg);    }}

数据集更改后，通知适配器有更改，并且将RecyclerView的滚动条滑到最后一个元素

 adapter.notifyItemInserted(msgList.size() - 1); recyclerView.scrollToPosition(msgList.size() - 1);

1 1